ray-the-pilot

If you don’t have a CO2 controller there is no way to determine what the CO2 level is in your tank. Without a controller, the level will depend on the time of day, the location in your tank, the number quantity and health of plants and fish etc. These can result in a 100 fold variation in the level of CO2.

A drop checker only gives the approximate average CO2 level at one location and it does not control the level of CO2. It is really only a ballpark estimate under these conditions.

With a CO2 controller, the CO2 in your tank is always the same everywhere. There are no hot spots, dead spots, changes with plant and fish activity…no changes period. Now the average CO2 level at one location is the exact CO2 level for the whole tank.

BTW I haven’t calibrated my controller in 3 months and I know it is still OK.
Whenever I bump into my drop checker and knock it off the glass I clean and refill it. I clean and refill my drop checker more often than I calibrate my controller.

pjbc

Sorry but I don't agree with this sentence!

Yes, a Co2 controller give you a more stable PH/Co2,
but the circulation of water is essential for a good co2 distribution,
you can have dead/hot spots with or without the controller!

In my opinion, the controller, if correctly calibrated/used, will give you less fluctuation of PH/Co2
and the co2 bottle will last longer, but it's not essential!

The drop checker is a visual aid..... it will give you a visual alert if the controller "go mad"!

helgymatt

^What he said....but I better not get into this one!

You have to buy a $1000 meter to know if you have the SAME CO2 concentration ALL over your tank.

ray-the-pilot

<<With a CO2 controller, the CO2 in your tank is always the same everywhere. There are no hot spots, dead spots, changes with plant and fish activity…no changes period. Now the average CO2 level at one location is the exact CO2 level for the whole tank>>

This is not an opinion this is a scientific fact!

If you go here and open CO2 paper part 2 and go to table 3:
http://www.aquaticplantcentral.com/f...ontroller.html

You will see that there is only a statistically insignificant variation in CO2 levels in a typical CO2 controlled tank.

I think are referring to a (CO2 in = CO2 out) system. In these uncontrolled systems the range in CO2 levels can be almost 100 fold.
See Tom Barr:
http://www.barrreport.com/co2-aquati...-readings.html

ray-the-pilot

You can buy a good CO2 controller for $110.00

http://www.aquariumplants.com/Automa...22_p/pr209.htm

And a pH meter for $20.00

http://www.aquariumplants.com/pH_MET...0_p/pr1408.htm

helgymatt

Well I can't resist...

Ray, In your thread you say your papaper is published. Where?

You need to explain the CO2=CO2 out theory. And then explain why your tank has the same CO2 everywhere and Tom Barr's does not. Are you saying that because Tom is injecting CO2 at a contant rate during the day, the difference of CO2 concentrations he finds in his tank are only because of time? Do you mean that throughout the day the CO2 concentration will increase and then the CO2 does not get mixed evenly in the tank causing differences in CO2 concentrations? Surely the pump in Toms tank is mixing water throughout the tank and surely some areas of the tank do not get as mixed as well as others.
Please explain why the CO2 controller would be any different than a needle valve injecting the same rate of CO2 24/7 (forget photoperiods and plants for now)

You didn't explain if you have any plants in your tank. It would be nice to know if your tank is a box of water or a planted aquarium with places which may not have as much flow as others.

EDIT: I found how you mixed the water in your tank to get to equilibrium - you stirred it. Seems like a very logical way to equilbrilate the water! I know my tank doesn't stir itself to mix up the CO2 enriched water. I do have a pump for circulation, but I know that back corner and other areas of my tank have hardly NO flow. How would the CO2 measure in those area of the tank?

Also, for the record means and standard errors are not "scientific fact". Maybe you can do some more powerful statistical analysis and then have a stronger case.

And BTW, I am not saying controllers are no good. I'm actually considering buying one. I just don't understand your logic.

Engold

A drop checker is really valid if the known kh is equal to the aquarium's kh value. Plus the pH probe must be routinely cleaned and recal on a regualr basis, at least monthly recal.. but ultimately.... how does your tank look and are the fish gasping for air on the surface. If everything is lush and flourishing... leave it alone... you must be doing something right

Later!

ray-the-pilot

Your question about publication is amusing! The fact that the paper is in the public domain and you can reference it, says that it is published. If you are asking whether I was paid for the rights to the paper; not yet so far.

If you look at table 3 you can see that the CO2 level stay constant over time and location to within a statistically insignificant +/- 2ppm. This is datum. Data are scientific facts!

The tank was NOT stirrer during the collection of the data for the distribution study. Only the normal tank circulation was used to mix the water.

The tank was only stirred to prepare the standard curve. This was necessary because a lot of CO2 was added each time and I didn’t want it to outgas waiting for the tank to equilibrate.

If you go into my profile you can find the details of the tank as well as a picture.

helgymatt

standard deviation and standard errors are not scientific facts! Any scientist knows this. Do a real statistical analysis.

You didn't answer any of the other questions. I want you to explain to me in detail why Toms tank has different levels of CO2 all over his tank when he uses a needle valve to inject the same rate of CO2 into the tank all day.

ray-the-pilot

I already answered this question before. I suggest that you go over the post "Why live with a wood burning stove."

If you have any real desire to understand this please do it in a PM. This is way off topic for this thread.